aakashns

const fromDb = (db, dispatch) => {
  db.ref('/message').on('value', data => {
    if (data.val()) {
      dispatch({ type: 'SET_MESSAGE', payload: data.val() });
    }
  });
};

aakashns

const fromStore = (state, db) => {
  db.ref('message').set(state.message);
}

aakashns

const linkStoreWithDb = (fromDb, fromStore) => {
  return (db, store) => {
    fromDb(db, store.dispatch);
    store.subscribe(() => fromStore(store.getState(), db)
  }
}

aakashns

const linkMessage = linkStoreWithDb(fromDb, fromStore)
linkMessage(firebase.database, store)

aakashns

let mustWrite = true; // Should we write the database?

const fromDb = (db, dispatch) => {
  const listener = db.ref('/message').on('value', snap => {
    if (snap.val()) {
      mustWrite = false; // Don't write the next dispatch
      dispatch({ type: 'SET_MESSAGE', payload: data.val()});
      mustWrite = true; // Done! Start writing again
    }
  });

aakashns

const linkStoreWithDb = (fromDb, fromStore) => {
  return (db, store) => {
    const unlinkFromDb = fromDb && fromDb(db, store.dispatch);
    const unlinkFromStore = fromStore && store.subscribe(() => fromStore(store.getState, db));
    
    const unlink = () => {
      unlinkFromDb && unlinkFromDb();
      unlinkFromStore && unlinkFromStore();
    }
    return unlink;

aakashns

 componentDidMount() {
  const { store } = this.props.store;
  this.unlink = linkStoreWithDb(fromDb, fromStore)(
    firebase.database(), 
    store
  );
}

componentWillUnmount() {
  this.unlink();

aakashns

const linkStoreWithPath = (path, actionCreator, selector) => {
  return (db, store) => {
    let previous = selector(store.getState());
    let mustWrite = true;

    const fromDb = (db, dispatch) => {
      const listener = db.ref(path).on("value", snap => {
        if (snap.val()) {
          mustWrite = false;
          dispatch(actionCreator(snap.val()));

aakashns

const messagePath = '/dummy';
const messageActionCreator = (value) => ({
  type: 'SET_MESSAGE',
  payload: value
});
const messageSelector = (state) => state.dummy;

const linkMessage = linkStoreWithPath(messagePath, messageActionCreator, messageSelector)

aakashns

#!/bin/bash
# install dependencies
sudo apt-get update
sudo apt-get install -y build-essential
sudo apt-get install -y cmake
sudo apt-get install -y libgtk2.0-dev
sudo apt-get install -y pkg-config
sudo apt-get install -y python-numpy python-dev
sudo apt-get install -y libavcodec-dev libavformat-dev libswscale-dev
sudo apt-get install -y libjpeg-dev libpng12-dev libtiff5-dev libjasper-dev